Liquid fuel-burning apparatus



July 29, 1930.

G. GOODRIDGE A LIQUID FUEL BURNING APPARATUS Filed Aug. 16. 1927 2 Sheets-Sheet l ImvewZoT;

MM f2??? July 29, 1930. G. E. GOODRIDGE 1,771,979

LIQUID FUEL BURNING APPARATUS med Aug. 16, 1927 2 Sheets-Sheet 2 Patented July 29, 1930 NITED STATES- PATENT OFFICE LABD, INCORPORATED,

CHUSETTS GEORGE E. GOODRIDGE, 01' READING, MASSACHUSETTS, ABBIG'HOR TO ARTHUR H. BAL- OF BOSTON, MASSACHUSETTS, A CORPORATION 01 IABSA- LIQUID-TUEL -BUBNING AIPABATUB Application filed August 10, 1987. Serial Io. 218,888.

This invention relates to liquid fuel burning apparatus and consists in improvements designed to sim lify, refine and add to the efiiciency of suc apparatus.

The invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specific embodiment thereof, while its sco will be more particularly pointed out in t e appended claims.

In the drawings:

Fig. 1 is a lan view of the principal operating parts 0 one form of fuel burning apparatus and showing the relationship of the fuel delivery mechanism and burner nozzle to the combustion chamber of the heater- Fig. 2 is a central, sectional elevation ta en through the burner nozzle and pump-containing supply chamber, showing the parts on a somewhat larger scale;

Fig. 3 is a sectional elevation taken through the supply pump on the line 3-3 in Fig. 5;

Fig. 4 is a central sectional longitudinal elevation on the line 4-4 in Fig. 5, showing the details of the float controlled air valve and the fuel cut-oil valve;

Fig. 5 is a plan view on a scale larger than that of Figs. 1 and 2, showing the intermediate supply chamber, the pumps and the float-controlled regulating device and the additional level responsive control devices arranged therein; and

Fig. 6 is a partial sectional elevation taken on the line 6--6 in Fig. 5.

Referring to the drawings and to the embodiment of the invention which is therein shown for illustrative purposes, a liquid fuel burner comprising the burner nozzle 11 is operatively related to the combustion chamber 13 of any suitable or usual heating device and connected to the burner supply pipe 15, the latter arranged to discharge through the nozzle and into the combustion chamber an atomized mixture of oil or other liquid fuel with air or other gaseous substance, the fuel being herein assumed for the purpose of illustration to be oil. I

To supply the burner, a main, vented reservoir or supply tank of relatively large capacity is provided, which is indicated diaof the pump grammatically at 17 in Fig. 1. This is ordinaril located at a point away from the burner. in intermediate, relatively small capacity supply chamber, however, is provided located in relative proximity to the burner, there being provision for delivering oil to the su ply chamber from the main reservoir 17 an for maintaining the oil in the supply chamber at an approximately constant leve In connection with the supply chamber, there is here provided a power-driven de liver pump drawing its supply from the supp y chamber and adapted to deliver the commingled oil and gas through the delivery pipe 15. The small capacity supply chamber is in the form of an enclosed box-like casing 19, the bottom or bed plate 21 of which is extended at 23 to form an adjacent support for the driving motor 25. The bed plate, with its supported motor and casing, is preferably mounted in close proximity to the burner nozzle.

For drawing the oil from the intermediate reservoir and supplyingit to the supply pipe 15, a delivery pump is employed, the casing of which is indicated at 29 (Figs. 5 and 6), this being preferably of a rotary positive of the delivery pump is indicated at 31 and the pump delivery is connected directly to the burner supply pipe 15.

As shown 1n the drawings, pump 29, instead of being mounted with the motor on the extended bed plate 23, is herein shown as contained within the supply chamber itself and enclosed by the wal s thereof and by the cover 33 of the casing, the frame members 35 and 37 of the pump being supported on the two lugs or pedestals 39 and 41 which project upwardly from the bottom of the casing so that the working parts of the pump are raised above the normal level of the oil therein. A driving or rotor shaft 43 extends through the opening in one of the side walls of the casing, also well above the normal level of the oil, and connects externally with the shaft of the motor 25 so as to be driven thereby.

To permit the oil delivery pump 29 to draw from the supply chamber a mixture of air the delivery 1 vice is provided. For this and oil, a suitable and ad ustable mixing deurpose the suction pipe 31 of the pump is cut downward- 1y so that its end (see F1 5. 2 and 6) dips below the normal level of t e oil therein and is provided with an air and oil mixing device, generally similar to that disclosed in m Patent No. 1,629,032, dated May 17, 1927. riefly, this involves the employment of a sleeve valve 45 adapted to be adjustably turned by the dial 47 on the down-turned end of the fixed pipe 31. The ipe 31 is provided with an oil admission ori ce in the form of a slot 49 cooperatively related to an opening 51 in the sleeve 45, so that by turning the latter an aperture of varying size-ma be made available for the suction of oil t rough the suction pipe 31. To regulate the amount of air admitted to the i e 31, the latter is provided above the diaF l with an air orifice in the form of a slot.

Cooperatively related to the aforesaid air orifice is an outer air valve 53 in the form of an outer sleeve having an overlapping slotshaped orifice 55 and secured to a second dial 57. By turning the dial 57, the air-adjusting valve or sleeve 53 may be set at different positions to vary the air opening through the pipe 31, and thereby to vary the amount of air admitted and to adjust the proportion of air and oil delivered by the pump to the burner.

A substantially constant level of oil within the supply chamber 19 is maintained, the means herein utilized for such purpose comprising asupply pump, adapted to deliver oil from the main reservoir 17 into the supply chamber, employed in conjunction with a float-controlled valve desi ned to regulate the supply in accordance with the needs of the burner.

The oil supply pump, the casing of which is represented at 59 (see Figs. 5 and 6), is also preferablyof the rotary positive displacement type, both the supply pump and the delivery pump in the illustrative form of the invention ing of the construction described in my aforesaid Patent No. 1,629,- 032. Such construction is indicated in the cross sectional elevation of the supply uinp shown in Fig. 3 and the longitudina section shown in Fig. 6, and is characterized by the provision of a rotor 61 (Fig. 3) eccentrica ly mounted within a c lindrical pump chamber and provided wit radially movable blades 63 which, as the rotor is revolved at a high speed, draw in the pumped fluid, whether liquid, gaseous, or both, from the ported suction chamber 65 and force the same gpt through the ported discharge chamber The oil supply pump is also mounted within the'box-like casing 19, being herein shown as fastened to the frame piece 35 of the delivery pump 29, and its rotor being driven by and with the motor shaft 43 with the delivery pump, so that the supply pump operates only with and during the operation 0 the main delivery pump. Since both pumps, together with the air mixing valve, float and float-controlled valve, are located within the supply chamber, there is not only secured a compactness of construction and arrangement, but any drainage or leakage from either pump will pass into the body of liquid contained therein and be delivered by the delivery pump to the burner.

The suction pump 59 draws its supply of oil from the tank 17 under the control of a compound valve hereinafter described, such valve being contained within the barreldike casing 69 supported by the bracket 71 on one of the walls of the casing 19. The suction pipe 73 of the suction pump is connected to the supply chamber 75 formed in the casing 69 (see Fig. 4) which chamber communicates through the oil supply orifice 77 with an oil chamber 79, the latter in turn being connected through the pipe 81 with a filter 83 of any usual construction. The filter 83 is connected through the supply pipe 85 (see Fig. 1) with the main reservoir tank 17. The discharge pipe 87 of the oil suction pump extends u wardly and then laterally and downward y to discharge its delivery direct- 1 into the chamber so that-any oil passing through the pump gravitates into the chamber and acts to replenish the supply thereof.

To limit the amount of oil delivered by the pump to that required to replenish the actual oil consumption by the burner and maintain a substantially constant level in the chamber, there is provided an air admission orifice connected to the suction side of the pump, herein, that part of the suction conduit which is subject to suction only, and a float-controlled valve controlling the admission of air to said orifice so arranged that the pump draws from the main reservoir a minimum quantity of oil sufficient only to maintain the required level, the valve adjustment and arrangement being such, however, that in actual use under ordinary conditions there is a slight but substantially uniform flow of oil to the chamber, the normal, float-controlled position of the air valve causing the pump to draw a relatively large amount of air and a relatively small amount of oil.

To this end there is provided a float 89 connected to the float arm 91, which latter extends through a slot in the valve casing 69 to which it is pivoted at 93. The free end of the arm (see Fig. 4) is connected to the movable pin 95 within the casing so that the latter has a reduced up or down movement within the casing following the down or up movement respectively of the float 89. Fitted to slide Within the bore 97 of the valve casing is the main, airvalve head 99, into the lower end of which is threaded the end of the pin moves upwardly, however,

- ther upward movement )5. The valve head 99 carries at its up 1 and the valve plate 101 in the form oi a leather washer which controls an air port 103 connecting the supply chamber 75 with an air chamber 105, the latter havin free communication with the air space in t upper part of the casing 19 throu h one or more air admission openings 107. &'hen the float descends the valve head 99 is raised and in its extreme upper position brings the washer 101 into. firm seatin contact with the valve seat 109, the latter being in the form of an annular ridge, and positively closes the air port 103 against the admission of air. The relation of the valve to the pump suction ipe is such that the suction of the pump tend; to

maintain the valve firmly seated when thelatter is moved to its fully closed position. 011 I the other hand, when the float rises, the valve@ sit-ion as is j the oillevel, the main air valve, after head is lowered to some such shown in Fig. 4, withdrawing t ewasher 101' from the va v to admit air to the supply chem auxiliary valve to be describe In the normal operation of the burner, and with the oil level approximately what is required, the main air valve occu ies some such position as is represented in i 4 and 6 and the control of air to the sup y chamber 7 and the suction conduit of t e pump is regulated b an auxiliary air valve in the form of a pm 111 having a tapered shoulder adapted to seat against the tapered walls of the mouth of the air port 103. The valve pin 111 is slidably mounted in a bushing 113 fixed in the end of the valve head 99 from which it protrudes throu h the seating washer 101. The lower end 0 the pin 111 is provided with a shouldered enlargement 115 normally seating against the end of the bushing through the action of a spring 117, the opposite crgd of which abuts against the end 0 the pin 9 The relationship between the auxiliary valve 111, and the main valve head 99, therefore, is such that when the valve head moves downwardly to an extreme position it may.

act to withdraw the auxiliary valve from its seat through the positive engagement of the bushing 113 with the shoulder 115. When it the auxiliary valve moves with it until it seats against the tapered walls of the air port, after which furof the main valve head takes place relatively to the auxiliary valve, the spring 1 17 yielding to permit such movement and serving to at increased seat ing pressure on the auxi 'ary valve as the head 99 continues to rise.

The air valve is so desi ed and adjusted that at the normal desiredd dvel of the oil the main air valve is wide open while the auxiliary valve, only partially closes the air port permitting a small amount of air to enterthe e seat and openingethe air portif r and pump I suction, except as further reg lated by the h fi t eair ori ce,

"rise until the latter. If the amount of air enterin is too great to yield the required amount 0 oil replenishment, the oil level will drop, lowerin the float and gradually raising the valve hea 99 whichin turn will raise the auxiliary valve increasingly reducing the air supply. If the condition oftoo little oil supply continues, the head will continue to rise, first partially seating the air valve and further reducing the supply of air, and then more firmly seating the air valve under the action of the s ring and still further reducing the air supp In the-normal action of the burner, however, the air valve will soon reach a condition of balance, in which it will tend to remain without substantial change and where the quantity of air, admitted will limit the oil sup ly tosubstantially that required for replenishing the consumption by the burner. In the event of an abnormal lowerin of rst eating the auxiliary valve, will continue to washer 101 positively seats against the valve seat 199, completely closing cutting ofi all an supply, and causing the suction pump to deliver oil at its full capacity.

In the event of an abnormal rise in the oil level, the valve head 99 will descend and withdraw the air valve so far' from its seat as to open the air port to the full sup 1y of air which is sufficient to prevent furt. er deliveryrof oil by the suction ump.

he range of action 0 the air valve in respect to the variation of available area of air opening is such that in actual usage, and with the burner flame and the withdrawal of oil by the delivery pump continuing, tomary, at a substantially uniform rate, the oil level may beheld at an almost constant point. The float and valve, as stated, tend to assume a balance condition where a constant amount of air is drawn through the air orifice and a substantially continuous supply of oil is withdrawn from the tank and elivered by the pump, this constant supply corresponding as is 'custo the amount of oil consumed by the burner.

That is to say, the valve and float may be so adjusted that the replenishment, instead of being intermittent, becomes substantially constant.

Such an arran ment results in marked advantages in an 011 burner of this description.

With the described arrangement, therefore, the load or duty placed on the suction pump, and thereby on the motor, isreduced to a minimum and actually to a very small amount. This factor lessens the ssible detrimental effect of variations in the'load on the action of the main delivery 'uo pump, the functioning of which should be uniform and regular in order to assure a uniform mixture and uniform combustion at the burner. As contrasted with systems where a supply pump is em loyed to draw a large and surplus amount oil from the main tank and return thereto the excess of oil above that required for replenishing the consumption by the burner, the pump in the herein described arrangJement not only operates under considera ly less load, but also with considerably less noise. This is due not only to the fact that a lesser amount of oil is required to be drawn from the reservoir and passed through the pum but also to the fact that rotary, positiveisplacement pumps of this type generally tend to operate with less noise when pumping commingled gas and oil than when pumping oil alone. Since the system of reguaction in the burner, and

lation is very sensitive and delicately responsive to changes in level, an almost constant and unvarying level may be maintained in the supply chamber. This is particularly important where the. delivery pump is required to supply commingled air and oil and where the proportion of the mixture is afiected by the level of the oil in the chamber, for under such conditions the level should be maintained as nearly constant as possible to secure uniform and proper conditions of combustion at the burner. The small amount of oil which passes from the tank to the pump also minimizes the effect of any possible leakage whichmay occur between the tank and the supply chamber.

This system of regulation, therefore, not only reduces the noise and the load on the motor, but tends to maintain a uniformity of articular-l in respect to the functioning o the main elivery pump.

In association withthe described means for maintaining a substantially constant oil level in the chamber 19and a substantiall constant replenishment of the consumed oi means are provided to additionally safeguard the feeding devices against abnormal or unusual conditions which mi ht result either in flooding the chamber wit oil or in so interruptin the supply as to drain the chamber. or re uce the oil evel therein to an abnormal degree.

To prevent the flooding of the chamber, due to any condition causing an abnormal or excessive flow of oil from the main tank 17 to the chamber over and above that re uired for replenishment, as, for exam le, t e attempt to fill the main tank under eavy tankwagon pressure and with the main tank vent pipe sto ped or partially stopped, there is provide in the oil chamber 79 an excessoil safety or cut-oif valve 119 in the form of a leather washer mounted on a shouldered bushing 121 and fastened to an upward extension 123 of the auxiliary valve 111 by the washer 125 and screw 127, the latter threaded into the end of the extension 123. The valve extension 123 passes through the air port 103 with sufficient clearance to provide the necessary air supply through the air port when the air valve 111 is open.

The excess-oil valve 119 is operatively related to a valve seat 129 in the form of an annular ridge so as to control the oil supply port 77, the relation being such that, when the valve is in its normal, raised position, oil may pass freely from the suction pipe 81 to the oil supply chamber 79 and through the oil port 77 but when depressed the valve is adapted to seat on the valve seat 129 and cut off all the su ply of oil which can pass from the main tan to the chamber.

Within the range of movement covered by the auxiliary valve 111 and the valve head 99 during the normal operation of the burner, the excess-oil valve 119 is held above the valve seat 129 so that it offers no interference with the free flow of oil to the pump suction pipe 73. In case of an abnormal rise in the oil level, however, the valve head 99 descends, withdrawing the air valve 111 from its seat and finally opening the air port to the full admission of air to the ump suction and rendering the pump ine active to draw oil from the tank. If the flow of oil still continues and the oil level further rises, the valve head will continue to move downward and finally seat the oil cut-oil valve 119 against its seat, positively stopping further flow of oil through the p1pe 81. T e cut-oil valve moves to its closed rection of flow of the oi through the oil port so that, if such continued flow is caused y any extraneous pressure, such as the tankwa on pressure applied at the'main tank, suc pressure mere y results in more firmly seating the valve 119 on its seat and insures against an flooding of the chamber.

As a sa eguard against the exhaustion of oil in the chamber 19, and the abnormal lowerin of the level therein, such as might result from the failure of the oil supply to respond to the action of the suction pump due to exhaustion of the oil supply in the main tank, stoppage in the suction pipe or other causes, there is provided a device which is designed automatically to open the circuit for the motor operating the two pumps, thereby to stop the operation of the burner, such device being also arranged to open the motor circuit in the event of an abnormal rise in the oil level so that the operation of the burner may be stopped in the event that any of the feed re lating devices fails to function as intendeg for any cause whatsoever.

For this purpose ,there is rovided a control member in the form of a ollow float 131 which is positioned in the fuel body of the chamber and guided in a substantially vertical path by the guide-rod 133. The float 131 is connected by the link 135 to the arm osition in the dithe same. One end of 137 attached to the rock shaft 139 which is journaled in the casing and extends across t e rock shaft 139 protrudes through the casing where it is secured to the rocker frame 141, the latter carrying a mercoid switch in the form of a glass tube 143, with switch contacts 145 at one end. The

movement of the frame and tube is limited by the stops 147 and 149, the stop 147 therefore also limitin the upward movement of the float under t e buoyant action of the oil. The tube 143 contains a quantity ofmercury 151 and the switch contacts 145 are in the main motor circuit. When the frame and its tube are ti ped to one extreme sition which is fixed by. the stop in 147, ti: mercury flows to the low end 0 the tube and bridges the contacts 145. When the frame is tipped to the op site extreme position against the stop 149, t e mercury flows to the opposite en of the tube away from the contacts and opens the motor circuit. As the fuel level rises in the supply chamber, the float 131 rises and,

when some substantial amount of oil is present, brings the rocking frame against the stop 147 so as to tip the tube to short circuitthe switch contacts 145 and maintain the motor 131, however, is .2

I e, float, are substantially a ove t e I ment being such that the float circuit closed the float bein' prevented by the stop 147 from risinglfurt er. This condition rsists during t a normal operation of the urner. "The up r part of the float rovi ed with a series of 'tion of normal working limits of the oil level, the arrangeis adapted to maintain 1ts switch-closing 'tion within such reasonably wide variations in oil level as may be had in'the normal or usual operation of the burner.

If, however, the oil level rises to an abnormal height, either through failure of the feed regulating devices to function, or for any other cause, the oil flows into the interior of the float and the latter loses its buoyancy and demends drawing down the link 135 and turning the rock shaft-to tip the switch frame inst the sto nings 153 whic in the u per 149 and open the motor circuit. On the 0 er hand, if the fuel level drops, when it "finally reaches a point indicating some serious disarrangement of the'fuel feeding devices to an abnormal P 3mg Therocker frame 141 is so weighted. that it requires the buoyancy of the float to maintain it in its upper or closed position against the stop pin 147. If the lifting efiect of the float is withdrawn for any reasonwhatever the frame immediately tips the switch to an open position.

While I have herein shown and described for the purpose of illustration one s ecific embodiment of the invention, it is to e understood that extensive deviations may be made therefrom and modifications and wide variations made in the construction, form and relative arrangement of parts, all without departing from the spirit thereof.

I claim:

1. A liquid fuel burning apparatus having a burner, a main fuel reservoir, an intermediate supply chamber, a suction pump for suppging fuel thereto from said reservoir, and oat-controlled, level-regulating means for the intermediate chamber comprising a fluid supply passage connected to the pump suction and opening into said chamber, a

main valve for controlling said fluid supply 1 float, and an auxiliary valve having a tapered I seat within the main valve seat, said auxiliary valve being sprin -pressed to protrude from the main valve ut ada ted to move relativel to the main valve w en the latter is mov to its full seating position.

2. A liqgid fuel burnin apparatus comrising a urner, a main uel reservoir, an intermediate su ply chamber, a motor, means for supp fying fuel to said supply chamber, means or maintaining a substantially constant fuel-level therein, and additional, level-responsive, control means adapted to cut out said motor and stop the o eration of the burner in the event of an a normally high or abnormally low fuel level in the chamber, the same comprising a switch, a hollow float positioned in the fuel body of the chamber and having one or more openings in its u per part, a connection between the float an the switch, means to limit the rise of said float whereby said float descends in the event of an abnormal lowering in the fuel level or, due to the flow of liquid fuel to the interior thereof, in the event of an abnormal rise thereof, and. through its descent acts to move said switch and cut out said motor. Y

3. A liqpid fuel burmn' guzpparatuseomri a urner, a main reservoir, an intermediate supply chamber, a pump for supplying fuel thereto, a motor for operating said p a cut-out switch for the motor, fue aeggiatin means responsive to changes in e fue level in said chamber, and means to operate said switch to cut out the motor in the event of either an abnormall h or abnormally low fuel level in said clfite r, the same com rising a buoyant hol- 4 low member provide with one (3' mpfie openin in its upper part positione in e fuel bofi y of the chamber, a stop to limit the rise of member whereby in the event of an abnormally high fuel level it receives an overflow of fuel and descends, and a connection to said switch whereby indescending, due either to an abnormal rise or an abnormal drop in the fuel level, it actuates said switch to cut out said motor.

4. A H uid fue l burninguapparatus comprising a urner, a main e reservoir, an intermediate supply chamber, a pump for supplying fuel thereto, a motor for operating said pump, a cut-out switch for the motor, and a float in said chamber, the buoyancy of which holds the switch in a closed position, said. float havin one or more openings near its top so that it will flood and sink in case of an abnormal rise of the liquid fuel, thereby opening the switch.

5. A liquid fuel burning apparatus having a burner, a main fuel reservoir, an intermediate sup 1y chamber, a pump for supplying fuel t ereto having its suction connected to the reservoir, and float-controlled, levelregulating means fonthe intermediate chamber comprising a fluid-supply passage connected to the pump suction and opening into said chamber, a main valve controlling said fluid-supply passage and anauxiliary valve also controlhng t e fluid supply assage said auxiliary valve bein carried y sai main valve but movable re atively thereto.

6. A liquid fuel burning apparatus having a burner, a main fuel reservoir, an 1ntermediate su ply chamber, a pump for supplying fueltheretohaving its suction connect v to said reservoir, and float-controlled, level-regulating means for the intermediate chamber comprising a fiuid-suppl passage connected to the pump suction an openin into said chamber, a main float-connects controlling valve movable to open or close said fluid-supply passe and an auxiliary valve moved positively y said main valve in one direction but adapted to be brought to rest to permit relative movement of the main valve when the latter is moved in the opposite direction.

liouid fuel burning apparatus comprism a urner, a main fuel reservoir, an in-= terms 'ate su ply chamber, a pump for supplying fuel t ereto, a motor for operating said ump, a cut-out switch for the motor, fueleed-re latin means responsive -to chan es in t e fuel oval in the chamber, and additional level responsive means adapted to cut out said motor and stop the operation of the burner in the event of an abnormally high or abnormally low fuel level in the chamber, the same comprising a normally buoyant member positioned in the fuel body of said chamber and having means for limiting its upward movement, said member havin pro-' vision for losing its buoyancy and sinhn in the fuel in the case of an abnormally h1 h fuel level, and a connection between said member and said switch whereby in mov ing downwardly. due either to abnormally high or abnormally low fuel level, it acts to open said switch.

8. A fuel burning apparatus comprising a burner, a main fuel reservoir, an intermediate supply chamber, a pump for sup lying fuel thereto, a motor for operating t e pump, a cut-out switch for the motor, and a float in said chamber having one or more openings near its top to cause it to flood and sink through loss of buoyancy, means for limiting the rise of the float, and means for o ening the switch through the descent of the fi dat.

9. A liquid fuel burning apparatus having a burner, a main fuel reservoir, an intermediate supply chamber, a pump for supplying fuel thereto having its suction connected to the reservoir, a float, and float controlled regulating means for the intermediate chamber comprising a fluid supply passage connected to the pump suction and opening into said chamber, a main valve for controlling the supply passage, connections to the float to cause sa1d valve positively to close said passage on an abnormally low fuel level but to move to open position under level conditions approximating normal, an auxiliary regulating valve, and connections between said auxiliary valve and said float to cause said regulating valve, while the main valve is open, to control the admission of fluid from said chamber to the ump suction under relatively slight VEIiatIOHS from normal level conditions.

10. A liquid fuel burning apparatus having a burner, a main fuel reservoir, an intermediate sufaply chamber, a pump for supplyin fue thereto havin its suction connecte to the reservoir, an level regulating means for the intermediate chamber comprising a fluid supply passage connected to the pump suction and openin into said chamber, a main valve for controlling the su ply passage with connections throu h w 1ch said yo ve is responsive to changes in the fuel level in said chamber, said valve being connected positively to close said passage on an abnormally low fuel level but to move to open position under normal level conditions and an auxiliary regulatinghlvalve also having connect1ons through w ch it is responsive to variations in fuel level to control the admission of fluid from said. chamber to the pump suction under relatively slight variations from normal level conditions while the main valve is open.

-11. A liquid fuel burning apparatus havmg a burner, a main fuel reservoir, an intermediate supply chamber, a pump for supplying fuel thereto having its suction connected to the reservoir, and level regulating means for the intermediate chamber comprising a fluid supply passage connected to the pump suction and opening into said chamber, a mam valve, means connected to said valve to move the same to cloeq the su ply passage on an abnormally low fuel have and render'the full cagacity 9f the pump available but t0 move 17 level. conditions, an auxiliary regulating va1ve,'and means cpnnectd to the auxiliary valve to'move the same to control the supply assagemlder level conditions a proximatmg normahtherby t0 efiect a 0 use regulation of the fuel 'leveltduring the normal operation of the burner.

In shimmy, I hm signed y name to this Specification;

GEQR oonnmcm'.

a same to open posxtlon under normal 

